Following the United Nations' swift and stern rebuke of North Korea’s missile test over Japan, calls are growing to put more pressure on Pyongyang and tighten existing sanctions even further. Some observers, however, wonder what good that will do, in light of the North's persistent provocations as it faces its toughest sanctions to date.

In a statement, the Security Council condemned Tuesday's launch and what it called the North's "outrageous actions," but did not mention the option of new sanctions.

The United States says all options are on the table, but China – North Korea’s biggest ally – has put its focus more on repeating its call to return to long-stalled talks and for all sides not to take any steps that would further heighten tensions.

China’s foreign minister, Wang Yi, Wednesday warned against unilateral actions by individual countries against North Korea, arguing that such steps violate international law.

Unilateral sanctions

In recent weeks, the United States and Japan have announced unilateral sanctions on Chinese firms aimed at curbing the flow of money to the North.

A new round of sanctions that went into effect earlier this month is the toughest ever in history, but not enough to stifle North Korea’s missile development, according to Zhao Tong, a fellow at the Carnegie-Tsinghua Center for Global Policy in Beijing.

“Any tougher sanctions, such as new bans on oil, labor and textile imports from North Korea, will seriously hurt the North's economic stability,” he said, noting China and Russia would be very cautious about implementing new sanctions.

China's Ambassador to the United Nations Liu Jieyi delivers remarks during a meeting of the U.N. Security Council on North Korea at U.N. headquarters in New York City, Aug. 29, 2017.

Air, sea blockade

Ding Xueliang, a professor at Hong Kong University of Science and Technology, says given that North Korea’s illicit trade ranges from $3 billion to $5 billion a year, sanctions need to amount to about $2.5 billion to have any impact.

Measures such as an air and sea blockade against the North also could be effective.

"All traffic in and out of North Korea, be it for commercial or military use, could be suspended; this is something the U.S. military could handle on its own,” said Ding. “But there are two things it may not be able to prevent and that’s the flow of goods from the North's connections to China or Russia."

North Korea shares a nearly 1,500-kilometer-long border with northeastern China and a short border with Russia.

​The latest round of sanctions has targeted coal, iron and seafood. The impact already is being felt in China, where local sellers of seafood have protested about the closure of the border and implementation of the ban. Analysts say it may take months for the impact of the current sanctions to truly be gauged.

Threats and talks

In the meantime, tensions continue to rise.

Earlier this month, North Korea threatened to fire missiles into the sea near Guam – an important U.S. military outpost in the Pacific – after President Donald Trump said Pyongyang would face “fire and fury” if it threatened the United States.

Following Tuesday’s launch, North Korea said more were to come, calling the missile test the first step in an effort to contain Guam.

Zhao Tong says that while the long game for both Washington and Pyongyang is to get back to the negotiating table, the two countries have opposite approaches.

“The U.S. believes that they should keep on exerting economic, political, diplomatic and military pressures on the North Korea to a certain extent that it is too much to bear so that the North will be forced to resume talks,” Zhao said.

The North thinks the U.S. isn’t convinced Pyongyang’s missile capabilities are feasible and solid, and that is keeping the U.S. from resuming talks with the North unconditionally, he says.

“Pyongyang will likely keep on testing its missile capabilities to the U.S. in the hope that the U.S. will acknowledge that fact and eventually treat the North as an equal party at the negotiation table,” he added.

North Korean leader Kim Jong Un inspects a long and medium-range ballistic rocket launch drill in this undated photo released by North Korea's Korean Central News Agency in Pyongyang, Aug. 30, 2017.

Potential miscalculations

China, too, is the focus of international pressure to do more to help with the situation on the Korean Peninsula.

During a visit Wednesday to Japan, British Prime Minister Theresa May urged Beijing to put more pressure on North Korea, saying it had a key role to play; but much like the United States could not force Cuba’s hand during the Cold War, China cannot force Pyongyang’s, says John Siracusa, a professor at the Royal Melbourne Institute of Technology University in Australia.

“There is always the possibility here of a Cuban missile-like solution, that is if China just announces tomorrow morning that they will guarantee North Korean sovereignty in exchange for an American pledge not to invade North Korea, I think we might save the day,” he said. “But the Chinese believe that the United States should cease and desist all military activities and exercises, and that the United States will not do that under any circumstances.”

Siracusa notes that unlike the Cold War, the situation on the Korean Peninsula now is more tense and the chance of war is high, standing at about 80 percent in his estimation.

“We have a kind of a 1914 situation, where all of these alliances are balanced against each other and we have all of these different players. Everybody is trying to calibrate what they are doing, etcetera,” he said. “We are looking at catastrophic potential miscalculations here, and I think any [damn] thing could trigger this thing off.”